Electrical terminal and method of making it



Jan. 4, 1944. c Y R' 2,338,485

.ELECTRICAL TERMINAL AND METHOD or" MAKING IT Filed June 12, 194:0

FIG. I

INVENTOR amaswm BY" 4? J1 mt A rrok/ver Patented Jan. 4, 1944 2,338,485 ELECTRICAL TERMINAL AND METHOD or MAKING uv I Charles M. Beyer, Orange, N. 1., assignor to Wc st-' ern Electric Company, Incorporated, New York, N. Y., a corporation of New York Application'Jun 12, 1940, Serial No. 340,035

' 3 Claims. (01. 29-15555) This invention relates to an electrical terminal and method of making it, and more particularly to a combined clamp and terminal for electrical apparatus and a method ofmaking it.

In the communications arts, especially in telephony and radio, there is use for a great numher and variety of electrical condensers. In

' many instances these are small in size and relatively delicate and even fragile in structure. Such small condensers are frequently made by depositingfllms'oi conductive metal, e. g., silver, on opposite sides of thin laminae of electrically insulating material, e. g., mica. These are then stacked as requisite and U-shaped members of relatively hard metal, e. g., nickel-silver, are clamped over opposite sides of the stack. both to hold the stacked laminae mechanically in place and to provide electrical connection to the metal films on the outer iaces'of the stack, suitable means being also provided to interconnect the several films in such manner as may be desired, e. an, soft metal ribbons with loops extending inwardly between adjacent faces oi adjacent laminae. Condensers of the type here considered may be found described in detail in applif cation'Serial No. 251,698, filed January 19, 1939, by J. R. Bransiord and A. T. Chapman, now Patcondenser provided with clamp-terminals conent 2,262,791, to which reference may be had i for particulars if necessary. Where such con densers are oi small size, itbecomes a difiicult problem to provide satisfactorily for mechanical support of the condenser and for electrical connection to the clamp-contact members.

An object of the present invention'is to provide a simple, durable and reliable clamp-terminal device for electrical apparatus and a method of 1 making it. I

With the above and other objects in view, the invention may be embodied in a clamp-ter minal device comprising a sheet metal member folded into U-shapeand'having a pair of par: allelslits oriented along and located .at the sides of the fold, so that when the member is vfolded, the portion thereof between the slits-will,

not bow but will remain flat to provide good welding anchorage fora rod-like or wire member whose end is butt-welded thereto.

Other objectsand features of the invention,

will appear from the following detailed description of. one embodiment thereof taken'in connection with the accompanying drawing in which the cal parts in the several figures and inwhicn Fig. 1 is a 'view in perspective of an electricali structed in accordance with the invention;

'Fig. 2 is a plan view Ora slit blank m the clamp member thereof;

Fig. 3 is an enlarged perspective view foldedclamp member; and

Fig. 4 is a similar view of the clamp member with the terminal member welded thereto.

of the In the embodiment of the invention herein disclosed, an electrical condenser has a body,-

generally indicated at 20-, and two identically similar clamp-terminals generally indicated at 30. For simplicity, the particular condenser selected for illustration has only one dielectric sheet, 1. e., one mica lamina 26. Films 22 of silver are deposited on and adherent to the opposite face of the lamina. A ribbon 23 of soft metal, e. g., lead, is folded overeach of opposite edges of the mica. iDne ribbon 23 extends over and makes contact with only one film 22; and the other ribbon 23 extends over and makes contact with only the other film 22. A sheet metal clamp member li fielded in U-shape,

embraces each ribbon 2d, a portion of the film 22 thereunder and a portion of the mica 2i, and is crushed together to hold these firmly together, the clamp being of some relatively hard metal, such as hard brass, nickel-silver, 'or the like, which will retain its clamping pressure on the parts within it. A rod-like terminal and sup= porting member 32,.e. g., a piece of tinned copper wire, is butt-welded at its end against the outer face of the fold of the member at, so as to lie generally in the plane of the condenser body.

JI'he blank for the member 8| (Fig."2),.to be folded substantiallybetween the dotted lines 33, is slit as at ti l, 34. These slits are preferably located about on the lines 33, although in some instances they may be between these lines, or.

of the slits, and so remains substantially flat its clamp 3| and'therefore in the plane of the y 2 assa-ieo body 20 of a condenser, made therewith. There is no material projection of the terminal beyond the thickness of the condenser and clamp, and

no material increase in the general bulk of the condenser. Because of the butt-welding of the wire end against the flat portion 38 of the member 3|, the weld can be easily made-sound and strong, a matter of importance, since in mounting such a condenser in complex apparatus, the

- two terminals 32 are usually used as supports for .the condenser-as well as for electrical connection. The terminals 32 are apt to be variously twisted or bent in such assembling of apparatus. It is found that if the slits 34 are omitted and the wire 32 butt-welded to the bowed surface of the clamp 3|, the weld is free quently imperfect, and in subsequent manipulation the wire may, and frequently does, crack away from the clamp.

Hence the preferred method of making,the clamp-terminal comprises the following steps in substantially the order given: first, the blank as shown in Fig. 2 is cut out of sheet stock; second,

the blank is slit as at 34 in Fig. 2; third, theblank is folded, as shown in Fig. 3, with the fold parallel to and chiefly between the lines defined by the slits; and fourth, the rod-like terminal 32 is butt-welded at its end' to the fiat portion 36 of the clamp between the slits 34, thus'producing the finished clamp-terminal 30, illustrated in Fig. 4, and ready to be applied to a bular' condenser body such as 20. If preferred th first twosteps noted may of course be combineddn a. single operation.

It is possible to squeeze the clamp member in place on the condenser body and subsequently butt-weld the terminal wire thereto. However, it

is thought preferable not to subject the condenser body, especially when it includes a lead ribbon in its structure, to the welding heat. While the clamp-terminal of the invention is illustrated and discussed as applied to use on a v tabular electrical condenser, it is not so limited.

.The embodiment of the invention herein disclosed is illustrative and may be variously modifled and departed from without departing from the scope and spirit of the invention as pointed 5 out in and limited only by the appended claims.

What is claimed is:

l. The method of making a clamp-terminal for electrical apparatus, which method comprises steps of forming a flat blank of sheet metal, makl0 1112: two parallel slits in the blank, folding the blank with the fold thus produced substantially parallel to and between the lines defined by the slits to make a generally U-shaped clamp member. having a flat and substantially unstressed portion between the slits and bowed and folded portions between the lines defined by the slits and on either side or the flat portion, and welding a terminal member of metal to the said flat portion of the clamp member.

2o 2. The method of making a clamp-terminal for electrical apparatus, which method comprises steps of forming a flat blank of metal having two parallel slits therein, folding the blank with the fold thus produced substantially parallel to and between the lines defined by the slits to make a generally U-shaped clamp member having a fiat and substantially unstressed portion between the slits and bowed and folded portions between the lines defined by the slits and on either side of the fiat portion, and butt-welding one end of a rod-like terminal member of metal to th said fiat portion oflthe clamp member.

3. A clamp-terminal for electrical apparatus comprising a clamp member of folded metal, having two parallelslits therein parallel to and substantially including between them the axis of the fold thereof, the portion of the sheet between the slits being flat and the portions between the lines defined by the slits and on either side of the said flat portion being bowed by the fold, and a terminal member of metal welded to the said fiat portion-of the clamp member. s CHARLES M. BEYER. 

